The present invention relates to a stripping device for stripping sheet-shaped objects from a roller. In particular, the invention relates to a stripping device for a foil winding repository for stripping sheet-shaped objects from a storage roller of the foil winding repository.
Foil winding repositories are known in the state of the art and are preferably employed as intermediate storage in apparatus for processing sheet-shaped objects, for example banknote processing machines or automatons for depositing and withdrawing banknotes.
A foil winding repository typically has one or two foils that can be unwound from corresponding supply rollers and rewound on these again. Furthermore, a storage roller is provided on which the one or several foils can be wound. Sheet-shaped objects, such as banknotes, are stored on the storage roller of the foil winding repository by winding the objects, after feeding them to the foil winding repository, on the storage roller together with the foils and storing them between individual layers of foil, wherein the foils are simultaneously unwound from the supply roller. The release of the sheet-shaped objects stored between the layers of foil is effected by unwinding the at least one foil from the storage roller, wherein the foil is rewound on the supply roller and the sheet-shaped objects are discharged, for example via suitable transport rollers or transport belts.
When outputting the sheet-shaped objects from the storage roller, it can occur that individual sheet-shaped objects remain adhering to the roller. To prevent this, a stripping device is employed which strips such adherent sheet-shaped objects from the roller.
Basically, stripping devices can also be used for stripping of sheet-shaped objects from such rollers which are provided in a device for merely transporting sheet-shaped objects, without the roller serving as a storage roller of a foil winding repository. Such rollers can be found for example in printers or similar devices.
Currently employed stripping devices include as stripper an elongated scraper that is tapering to a point at the end touching the roller. The scraper is configured to be elastic, preferably of an elastomer, and is pressed against the roller with prestressing during operation. In particular in connection with a foil winding repository the storage roller of which inherently has a radius that varies over time and an irregular roller surface, the following difficulties are encountered. The setting angle and the pressure with which the scraper is pressed against the roller vary depending on the radius of the roller and the surface structure of the roller. A too steep or too flat angle of the scraper can result in sheet-shaped objects adhering to the roller not being grasped by the scraper and consequently not being stripped. Further, there is the risk that, due to irregularities of the roller surface, the end of the scraper touching the roller temporarily loses contact with the roller surface. Here, too, it can occur that sheet-shaped objects adhering to the roller are not stripped off.